Single-chamber mini-solid oxide fuel cells operated at a lower temperature

The performance characteristics of a single-chamber solid oxide fuel cell (SOFCs) with micro-patterned electrode structures on the disc-type electrolyte were investigated. We selected Sm_0.2Ce_0.8O_2-x (samarium doped ceria, or SDC) as an electrolyte, SDC-NiO cermat as an anode, and SDC-Sm_0.5Sr_0.5CoO₃ (samarium strontium cobaltite) as a cathode for low operating temperatures (500-600°C). To fabricate complex micro-patterned electrodes on electrolytes, we used microfluidic lithography. First, patterned NiO-SDC anode was sintered at 1350°C for 4 hours, then SDC-SSC cathode was patterned and sintered at 1050°C for 8 hours, resulting in a coplanar-type, single-chamber SOFC in which the interdigitated electrode has a 100-μm line width and an anode-to-cathode distance of 100 μm. A reduction condition was proposed below 350°C using humidified hydrogen gas. The shape of electrode and microstructure was observed by scanning electron and optical microscopes. I-V characteristics of the SOFC were measured using a propane-air mixture gas by a DC source measure unit.